The present invention is generally related to wireless communications systems, and more particularly to fixed wireless systems provided with HomeZone service whereby subscribers are provided communications service, and billed accordingly, depending on whether or not a subscriber""s mobile station (MS) is located within one of its designated HomeZones.
The implementation of wireless communications systems throughout the world is growing rapidly. This can be seen by the extensive sales and marketing of mobile cellular phone service throughout North America as well as the rest of the World. Existing and emerging technologies include AMPS, TDMA, CDMA, and GSM just to name a few. In these systems, a subscriber of an MS is typically billed for calls at a rate determined by a plan contracted to by the subscriber of the MS, whereby the rate per minute may be based on the time of day, the amount of use and the geographical location of the MS during a call.
Another emerging wireless communication system is known as a fixed wireless system. In many parts of the world including Europe and Asia, subscribers are being provided with wireless communication transceivers e.g. mobile stations as their primary communication device for use within a residence, business and other defined locations. These fixed wireless transceivers are specially suitable where wireline services are to date not available, inadequate, or exceptionally expensive to install. With the decreasing cost of wireless transceivers and supporting infrastructure, those places of the world in need of new or upgraded communication systems are finding fixed wireless systems as economically attractive and versatile solutions.
In fixed wireless communication systems, a subscriber""s mobile station is assigned to one or more HomeZones. Each HomeZone defines a geographical home area in which the wireless mobile station is to receive and originate wireless calls at a predetermined low billing rate. While it is primarily intended that a subscriber will primarily use its mobile station within the HomeZone areas, these mobile stations may be transported by a subscriber outside the HomeZone calling areas and may be allowed to originate or receive calls outside the HomeZone area at another predetermined billing rate.
The HomeZone service allows telecommunications providers to define the HomeZone calling areas for their MSs, where the tariff for calls originated and terminated in one of the HomeZones is different than the regular wireless tariff. The HomeZone service is attractive for telecommunications providers wanting to offer both fixed wireless and wireless services to subscribers over one mobile phone. One of the significant costs in providing wireline services is laying copper to each subscribers home. HomeZone service eliminates this cost by using wireless systems which don""t require the cost of laying copper. The HomeZone service allows the provider to charge subscribers a particular tariff when they use their mobile station in one of their HomeZones at their wireline rate, and at another tariff when they use their mobile station outside their HomeZones at their wireless rate. The wireline rate is usually less expensive than the wireless rate. This attractive to consumers because they are charged the same low rates in their Homezone as they would have been charged by a wireline provider but without the hassle of multiple phones bills.
As part of the HomeZone feature, on call termination, the location of the mobile station must be determined before the call is routed to the network access element, such as a visitors mobile switching center (VMSC), currently serving the mobile station, so that the network can potentially disallow or reroute the termination if the subscriber""s mobile station is not in one of is HomeZones. There is a need to provide a method for determining whether a mobile station is located in one of its HomeZones, and also a method for speeding up the potential termination to the mobile station that may follow.
The present invention achieves technical advantages as a method of establishing call termination to a called mobile station in a wireless communication network which can be only allowed to receive call terminations in one of its HomeZones by determining the mobile station""s location and identity before completing a call termination to the network access element currently serving the mobile station.
In the preferred embodiment of the present invention, the method comprises first determining if a call termination received by a wireless communication network is a HomeZone type call. This may be done, for instance, at a gateway MSC by identifying prefix digits attached to the call. Upon determining that the call termination is a HomeZone type call, the location of the called mobile station to the cell level is first identified in the wireless communication network before routing the call termination to a network access element currently serving the mobile station. It is then determined if the identified location (e.g. serving cell of the mobile station) is within one of the mobile station""s HomeZones. If the mobile station""s location is determined to be within one of the mobile station""s HomeZones, then the call termination is routed to the network access element currently serving the mobile station, and the call termination is completed to the mobile station by the network access element currently serving the mobile station. Preferably, the network access element comprises an MSC, but could comprise other equivalent network devices. If the mobile station is determined to be outside its HomeZones, the call may be routed by the network to the mobile stations voicemail, or to an associated wireless phone number and billed accordingly.
According to the present invention, a mobile station radio link is established between the MSC currently serving the mobile station and the mobile station during the mobile station location process, wherein the call termination is completed to the mobile station on the same mobile station radio link. The radio link is preferably established by sending a PSI message from a HLR to the MSC currently serving the mobile station and paging the mobile station, whereby the mobile station then responds to the page with a page response to the serving MSC. If the mobile station is currently on a call, the location of the MS is known to the serving MSC and is returned to the HLR. If a subsequent termination arrives at the serving MSC, then the call termination to the mobile station is completed if the MS is configured to receive multiple calls e.g. call waiting, without establishing a new radio link between the MSC serving the mobile station and the mobile station.
A PAGE_RESPONSE message which includes the mobile station""s identity is generated in response to the page message by the mobile station. The identity included in the PAGE_RESPONSE message comprises preferably either the mobile station""s International Mobile Subscriber Identity (IMSI) or Temporary Mobile Subscriber Identity (TMSI). If the response contains the TMSI, the TMSI is used by the serving MSC to find the IMSI. The page response also includes the mobile station""s current Cell ID and the mobile station""s current location area code (LAC). The mobile station""s identity, LAC, and Cell ID are all sent by the MSC serving the mobile station to the home location register (HLR) of the mobile station. The mobile station""s identity, LAC and Cell ID are then sent to a service control point (SCP) of the wireless communication network. The SCP determines if the mobile station is in one of the mobile station""s HomeZones. If the SCP determines the mobile station is in one of its HomeZones, the SCP notifies the gateway MSC of the wireless communication network to complete the call termination to the mobile station. If the mobile station is determined to be outside its HomeZones, the call may be routed by the SCP to the mobile station""s voicemail, or to an associated wireless phone number and billed accordingly.
The present invention achieves technical advantages by determining the location of the mobile station to the cell level before the call is routed to the serving MSC, and speeding up the potential call termination to the mobile station that may follow.